A power distribution unit (PDU) is a type of power distribution sockets for a cabinet, which includes a plurality of sockets to be served as power sources to provide required power to for example a server and a storage system in a rack of a data center. The application of PDU can make the power distribution in the cabinet more neat, reliable, safe, professional and aesthetic. However, in order to prevent the power plugs of the server and storage system in the rack and the power sockets of the PDU from loosening caused by the human or other unintended conditions, there is a need to enhance the retaining force between the power socket of the PDU and the power plug.
The conventional power socket of the PDU can increase the retaining force between the power plug and the power socket by adding additional accessories. However, the additional accessories fail to match with the original socket structure completely, and does not facilitate to maintain the neat and aesthetic appearance of the cabinet. On the other hand, under the conditions of compliance with the original safety regulations, it is difficult to design the structures of the power socket and the power plug to match with each other. Moreover, the power socket designed to match with a specific power plug won't work with most other power plugs.
Therefore, there is a need of providing a power socket to enhance a retaining force between the power socket and a power plug and overcome the above drawbacks.